TOO LONG PLEASE READ. NEED HELP @Dr.Peterson @JeffM @Subhotosh Khan
SO I found a already given answer in this "https://www.quora.com/Why-do-the-denominators-need-to-be-the-same-when-adding-the-fractions"
I was going through Carol Hartman Shadwell & Alan Bustany answers
1: FROM ALAN BUSTANY ANSWER I QUOTE "
Numerators Equal
Suppose the numerator is a common value, n, then what is the value of n/b+n/d ? Suppose it is p/q then we can multiply through by qbd to get:
nqd/qbd+nqb/qbd=pbd/qbd
So our problem is reduced to a situation of denominators equal.
Denominators Equal
Suppose the denominator is a common value, m≠0, then what is the value of a/m+c/m ? Suppose it is p/m then multiplying through by m gives us:
a/m+c/m=p/m⇒a+c=p so--->a/m+c/m=(a+c)/m"
1:I did not understand what he is trying to tell in this particular quote other than "Denominators equal turns out to be much simpler "
2: he multiplied by qbd both sides num & denom to make denom equal ; does he found out the value of n/b+n/d or it is not neccesarry in this context ;he was trying to make denom same right?or he was giving us some instinct ? I have not got the logic why denom has to be equal after reading this.
2: FROM Carol Hartman Shadwell answer I QUOTE "
Likewise, in fractions, we add pieces of the same size. We add halves to halves and 12ths to 12ths but not halves and 12ths.To add 1/3 and 1/2 of a pizza, we have to do something first: rewrite them as fractions with common sizes on the bottom. (common denominators) The halves need to be divided into 3 equal parts to create 6ths and the thirds need to be divided into 2 equal parts to create sixths. The result is a pizza that is made of 6 equal parts. 3 out of the 6 equals 1/2 and 2 out of the 6 equals 1/3. Now add the sixths. 1/3+1/2=2/6+3/6=5/6 "
THE THIRDS PART FIRST: i was drwaing tiles and picturing it ;he says there is only one pizza out of which to take 1/3
1/3 looks like this:
|____|_____|___| each box is 1/3 ---->then i pick 1 one third slice÷ into 2 equal parts to create sixths -->|____|_____| two box each 1/6 worth
a equivalent pic of that one 1/3 slice box = 2 slices of (1/6)box look like just imagine there is a arrow from this box to upper 1/6th box|_________|
HALVES PART: then i take 1/2 of the same whole pizza or different pizza?IF same, I have already cut the pizza into 3 slices and taken 1 slice(1/3) and then divided into two sixths as shown above ; REMEMBER i have still two 1/3 slices left which i havent done anything ;now 1/2 means" i need to slice the pizza into 2 parts and consider 1 part right"; which part of already sliced pizza will i have to halve ;whether it is one of the two 1/3 slices which i think it might be or the already sliced 1/6th pizza.
i cannot drw the next pic of the 1/2 part as there are many possbilities ringing in my mind.
SO I found a already given answer in this "https://www.quora.com/Why-do-the-denominators-need-to-be-the-same-when-adding-the-fractions"
I was going through Carol Hartman Shadwell & Alan Bustany answers
1: FROM ALAN BUSTANY ANSWER I QUOTE "
Numerators Equal
Suppose the numerator is a common value, n, then what is the value of n/b+n/d ? Suppose it is p/q then we can multiply through by qbd to get:
nqd/qbd+nqb/qbd=pbd/qbd
So our problem is reduced to a situation of denominators equal.
Denominators Equal
Suppose the denominator is a common value, m≠0, then what is the value of a/m+c/m ? Suppose it is p/m then multiplying through by m gives us:
a/m+c/m=p/m⇒a+c=p so--->a/m+c/m=(a+c)/m"
1:I did not understand what he is trying to tell in this particular quote other than "Denominators equal turns out to be much simpler "
2: he multiplied by qbd both sides num & denom to make denom equal ; does he found out the value of n/b+n/d or it is not neccesarry in this context ;he was trying to make denom same right?or he was giving us some instinct ? I have not got the logic why denom has to be equal after reading this.
2: FROM Carol Hartman Shadwell answer I QUOTE "
Likewise, in fractions, we add pieces of the same size. We add halves to halves and 12ths to 12ths but not halves and 12ths.To add 1/3 and 1/2 of a pizza, we have to do something first: rewrite them as fractions with common sizes on the bottom. (common denominators) The halves need to be divided into 3 equal parts to create 6ths and the thirds need to be divided into 2 equal parts to create sixths. The result is a pizza that is made of 6 equal parts. 3 out of the 6 equals 1/2 and 2 out of the 6 equals 1/3. Now add the sixths. 1/3+1/2=2/6+3/6=5/6 "
THE THIRDS PART FIRST: i was drwaing tiles and picturing it ;he says there is only one pizza out of which to take 1/3
1/3 looks like this:
|____|_____|___| each box is 1/3 ---->then i pick 1 one third slice÷ into 2 equal parts to create sixths -->|____|_____| two box each 1/6 worth
a equivalent pic of that one 1/3 slice box = 2 slices of (1/6)box look like just imagine there is a arrow from this box to upper 1/6th box|_________|
HALVES PART: then i take 1/2 of the same whole pizza or different pizza?IF same, I have already cut the pizza into 3 slices and taken 1 slice(1/3) and then divided into two sixths as shown above ; REMEMBER i have still two 1/3 slices left which i havent done anything ;now 1/2 means" i need to slice the pizza into 2 parts and consider 1 part right"; which part of already sliced pizza will i have to halve ;whether it is one of the two 1/3 slices which i think it might be or the already sliced 1/6th pizza.
i cannot drw the next pic of the 1/2 part as there are many possbilities ringing in my mind.
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